The sun is a dynamic star, made of super-hot ionized gas called plasma.
The sun's surface and atmosphere change continually, driven by the magnetic forces generated by this constantly-moving plasma. The sun releases energy in two ways: the usual flow of light that illuminates the Earth and makes life possible; but also in more violent and dramatic ways--it gives off bursts of light, particles, and magnetic fields that can have ripple effects all the way out to the solar system's magnetic edge.
Solar activity follows a roughly 11-year cycle. This composite image shows the sun in extreme ultraviolet wavelengths about once a year over the course of a complete solar cycle.
A magnetosphere is the region around a planet dominated by the planet's magnetic field.
Other planets in our solar system have magnetospheres, but Earth has the strongest one of all the rocky planets: Earth's magnetosphere is a vast, comet-shaped bubble, which has played a crucial role in our planet's habitability. Life on Earth initially developed and continues to be sustained under the protection of this magnetic environment.
Earth is surrounded by a giant magnetic bubble called the magnetosphere, which is is part of a dynamic, interconnected system that responds to solar, planetary, and interstellar conditions.
Though space is about a thousand times emptier than even the best laboratory vacuums on Earth, it’s not completely devoid of matter.
The sun’s constant outflow of solar wind fills space with a thin and tenuous wash of particles, fields, and plasma. This solar wind, along with other solar events like giant explosions called coronal mass ejections, influences the very nature of space and can interact with the magnetic systems of Earth and other worlds. Such effects also change the radiation environment through which our spacecraft – and, one day, our astronauts headed to Mars – travel.